In order to linearly reciprocate an object to be transported such as a workpiece or a jig and a tool, a linear-reciprocating device is used so as to linearly reciprocate a moving block such as a slider or a table, to which the object to be transported is attached, along a guide rail of a support base. The support base is provided with a drive rod that reciprocates freely in a longitudinal direction of the support base, a protruding end of the drive rod is connected to a distal end of a moving member by a connection block, and the moving member is linearly reciprocated by the reciprocation of the drive rod. The drive rod is driven by a driving source such as a pneumatic cylinder or an electric motor.
By attaching the moving block to the guide rail via balls so as to interpose a lot of balls between the moving block and the guide rail, the moving block which reciprocates along the guide rail can be driven with a small rolling resistance. A lot of balls are housed inside a ball rolling path which is formed of a rolling groove having an almost semicircular shape and being provided to the moving block and a rolling groove having an almost semicircular shape and being provided to the guide rail, and the balls are moved while rolling inside the ball rolling path when the moving block is driven.
The following two types are known as such a ball slider that the moving block is attached to the guide rail via the balls. One of them is an infinite guide type provided with a return hole, that is, a ball circulation hole provided separately from the ball rolling path for circulating the balls between the ball circulation hole and the ball rolling path. The other is a finite guide type in which the balls are not circulated. Patent Document 1 describes the infinite guide type ball slider.